Polytechnic Association Proceedings. 753 



lively large feathery crystals. Guinia and strichnia are completeljr 

 precipitated even when diluted with 10,000 parts, by weight. The 

 precipitates are not soluble in ether, but are easily taken up by 

 alcohol, less so by water; aad they are redissolved in a surplus of 

 the reagent. 



BORNEO CA^VIPHOE. 



This variety of camphor, which commands in the Eastern mark- 

 ets about twenty-eight dollars per pound, is obtained from the 

 baru tree. The slopes of the hills on the eastern coast of Borneo 

 are covered with these trees. To gather the camphor, the tree is 

 felled and split; and in its center the gum is found. The average 

 amount taken from a tree is not less than ten pounds. The quality 

 of this camphor is superior to all other varieties. A small frag- 

 meat emits a very strong odor, and does not seem to lose its power 

 for several j-ears. Some idea of the estimate in which it is held 

 by the Chinese, may be had from the price it commands. Formo- 

 san camphor may be purchased for about sixteen cents per pound, 

 while the baru brings one hundred and seventy -five times more. 

 Mr. Torrey, an American resident of the Island, and having con- 

 trol of the northern territory, has lately brought to this country, 

 specimens of camphor, hard woods, and other interesting materials 

 which might be imported on a large scale with profit. 



In the liscussion following the reading of the item on " bronze- 

 colored iron castings," Dr. L. Feuchtwanger said that one kind oi 

 bronze coloring is made with platinum and plumbago. 



D. W. Bradley stated that he tried this bronze on clocks, and 

 found that it oxydized very much; but it is now claimed that this 

 objection has been removed. Suflicieut time, however, has not 

 elapsed to prove this. 



Dr. John B. Rich remarked that the amiory of the Seventh Regi- 

 ment, an iron building, was oxydizing very rapidly, so that fears 

 are entertained of its being seriously injured in a short time. Scales 

 after scales of rust are continually dropping ofi*. 



Mr. D. Blanchard said that all the iron columns he had seen, 

 after being taken down, and which had stood for a long time, 

 showed no signs of oxydization whatever. They presented the 

 grayish-blue appearance usual to cast iron when first cast. 



Dr. D. D. Parmelee stated that the oxydation of iron comes from 

 the decomposition of water in the atmosphere. An iron column 

 that permits the damp air to pass through it, will inevitably be 

 oxydized. 



riNST.l 48 



